chapter 7 Flashcards
cartilage is?
avascular bc the ecm provides all nutrients
ecm
solid and firm bc proteoglycans bear all weight
hyaline cartilage
-type 2 collagen
-proteoglycans
-multiadhesive groups
-fibrocartilage (type 1)
-has spaces/ lacunae
-synovial joints
-WILL NOT REPAIR ITSELF
TENASCINA ND FIBRONECTIN
ANCHOR CHON OT MATRIX
collagen types
-type 2
-type 9
-type 6
type 6
attached chon to matrix
3 types of proteoglycans
-hyluron
-chroitin sulfate
-keratan sulfate
hyluron
forms large proteoglycan (aggregan)
-allows diffusion
-formation of chon
-lets chon bear weight because of water movement
core protein
makes proteoglycan monomer (has a neg charge)
what do chon detect?
changes in the matrix that trigger ecm turnover
isogenous groups
-groups of chon
-cells recently divided
-secrete metanoprotionase (an enzyme that breaks down cartilage)
cytoplasmic basophilia
in chon, responsible for protein synth
does the ecm stain?
stains unevenly therefore the matrix is not a homogenous mixture
staining regions of chon
-capsular
-territorial
-interterritorial matrix
capsular/ pericellular matrix
-has the highest concentration of sulfates and therefore proteoglycans
-type 6 collagen
-also some type 9
type 6
binds integrin recptors on the cell surface and anchors the chon to the ecm
territorial
-surrounds isogenous groups
-type 2
-less type 9 than capsular layer
-stains less bc it has less sulfate and therefore less proteoglycans
interterritorial
surrounds the territorial and is btwn the groups of chon
endochondrial ossification
hyaline cart
remaining cart after growth
-becomes epiphyseal plate and adults have articular cartilage on ribs, nose, and trachea
hyaline cart is surrounded by?
perichondrium (connective tissue)
Where do new cartilage cells come from?
the inner layer of the perichondrium
what covers the surfaces of moveable joints?
hyaline
articular cart.
-contact bone on one side
-no perichondrium
-2 to 5 nm and 4 zones
zones of art. cartilage
-superficial
-intermediate
-deep
-calcified
superficial/ tangital
-pressure resistant
-type 2 (ARRANGED IN PARALLEL FASICLES)
-long flat chon
Intermediate/ transitional
-under superficial
-round chon
deel/ radial
-small round chon
-in perpendicular columns
calcified
-has a calcified matrix
-small chon
what separates the calcified and deep zones?
the tidemark
what makes elastic cart. elastic?
it has elastin in the matrix
- it is surrounded by perichondrium
what are the best stains for elastic cart.?
reorcinfuchsin and orcein
what is made of elastic?
ear and canal, eustachain tube and epiglottis
which cartilage does not calcify with age?
elastic cart.
fibrocartilage
made of chon
-it is a dense regular connective tissue with hyaline cart.
-they just have less cart. matrix
-no perichondrium
-round chon
-resist compression
-type 1 and 2
-can change the matrix even after it is snythesized
-lots of aggrecan
where does cart. develop from
mesenchyme
head
aggregates of ectomesenchyme that comes from the neural crest
chondrogenic nodule
-site of hyaline formation
-marks the start of hyaline formation
-mesenchymal tissue around it develops perichondrium
chondroblast
result of differentiation
-uses transcription factor sox-9
-move apart as they begin to deposit matrix
appositional growth
-comes from innerlayer of perichondrium
-trans factor sox9
-round nucleus
-perichondrium makes new chon
interstitial growth
-new cartilage comes from lacunae
-only possible because the chon retain the ability to divide
-daughter cells are together in lacunae until partition forms and move further away
-happens bc of new chon made by isogenous cell clusters
hyaline repair
ONLY IF THE DEFECT AFFECT THE PERICHONDRIUM
-repair= production of dense c.t.
hyaline repair
ONLY IF THE DEFECT AFFECT THE PERICHONDRIUM
-repair= production of dense c.t.hy
hylaine calcification
–forms calcium phosphate/ hypoaxalate crystals
when will calcification happen
when bones are growing and it happens btwn articular cartilage and bone when it is abt to be replaced by bone
calcification
-does not allow diffusion to happen, chon swell and die
chondroclast
enter cartilage on new b.v.
-come from bone marrow stem cells
-wherever cartilage in removes and are in lacuna
perichondrium layers
-outer layer= fibrous
-inner layer= cellular (for exernal growth)
what layer of the matrix stains more intensly?
capsule
what is lightly stained matrix?
matrix that has not matured yet
